Methylene disulfonate compounds are usable as pharmaceutical preparations for treating leukemia in animals, etc.
There are various known methods for producing a methylene disulfonate compound. For example, Patent Literature 1 discloses a method in which sulfonyl chloride is reacted with silver carbonate, and the resulting silver sulfonate is reacted with diiodomethane according to the following reaction formula. In the reaction formula below, R is a hydrogen atom or a methyl group.

However, such a production method has disadvantages in that the silver carbonate and diiodomethane used are expensive and the reaction is slow.
Patent Literature 2 discloses a method in which alkanedisulfonic acid, etc., is reacted with methylenediacetate, etc., according to the following reaction formula. In the formula below, R′ and R″ are independently a hydrogen atom or an alkyl group.

However, such a production method is not industrially suitable because the methylenediacetate, etc., used is expensive and not readily available, and moreover, alkanedisulfonic acid, which is a starting material, is also expensive.